Aside from being a human, which is a very relevant creature type in Commander, Modern and basically every other MTG format, Esper Sentinel is good because it reads: Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays X, where X is Esper Sentinels power. Its a bit like Rhystic Study, but the cost can be far higher if youve got things that make humans stronger or you can put +1/+1 counters onto Esper Sentinel
I guess you don't get anything back
For six mana, Muldrotha is a black, green, and blue 6/6 that allows you to play one permanent of each type from your graveyard one each of your turns
They also contain double-sided helper cards with tips on how to get started, find stores, and learn a lot more about the game
This enchantment, on the other hand, does everything
Thanks to her inherent ward ability, Gisa can require a hefty investment by opponents to take off the field